Just how much fat, protein, carbohydrates, and fiber do you need on a 1200 calorie diet? I’ve been asked this question a number of times and I’ve given responses for individual nutrients. Today I’d like to share with you how to assess what you need for each of the macronutrients (fat, protein, carbohydrates) and fiber all in one place.

The National Academy of Sciences is the government group that has had the responsibility for determining nutrient needs for the American public since 1941. As you might imagine the recommendations of the Academy have changed over time as new information becomes available with ongoing research.

Until the 1990s the recommendations of the Academy were called Recommended Dietary Allowances or RDAs. More recently, the recommendations were updated to be more comprehensive in nature. The new recommendations are now called Dietary Reference Intakes or DRIs.

The DRIs reflect a number of different measures. Of these, the easiest one to work with is the Acceptable Macronutrient Distribution Range. How’s that for a mouthful?

What you will want to remember are the general guidelines for each of the macronutrients:

Protein: 10-35% of total calories
Fat: 20-35% of total calories
Carbohydrates: 45-65% of total calories

The reasons for this breakdown or range of values are complicated. However, no distribution will ensure you are getting enough of each of the various nutrients if you aren’t getting enough total calories in the first place. Please read my article on how to determine a safe and adequate minimum number of calories for you on a low calorie diet. Most women need more than 1200 calories as a minimum! (1200 Calorie Diet: Getting Started!)

O.K., if you have determined that 1200 calories are enough for you while on a low calorie weight loss plan then the values you are looking at equal:

Protein: 10-35% of total calories
120 - 420 calories
30 - 105 grams

Fat: 20-35% of total calories
240 - 420 calories
approximately 27 - 47 grams

Carbohydrates 45- 65% of total calories
540 - 780 calories
135 - 195 grams

(To calculate the grams of protein, fat, and carbohydrates you need to know the potential energy or calories that each gram might provide. In general, each gram of protein and carbohydrate will yield 4 calories. Each gram of fat will yield 9 calories. So just divide (protein or carbohydrate) calories by 4 to determine protein and carbohydrate grams. Divide (fat) calories by 9 to determine the fat grams.)

Your need for fiber is influenced by the number of calories you consume. However to keep things simple I suggest you keep in mind the general guidelines for fiber needs by age and sex. Adult women less than 50 years of age have a recommended fiber intake of 25 grams a day. Women over the age of 50 have a recommended fiber intake of 21 grams a day. If your dietary fiber intake approaches or exceeds the recommended level make sure you are getting plenty of water in your diet.

Please note that these recommendations are for the average person. If you have diabetes or other health challenges you need to follow the advice given to you by your medical doctor or dietician.